System and method for providing automatic load balancing and redundancy in access port adoption

ABSTRACT

A computer network as described herein includes multiple wireless switches cooperating with wireless access devices. The wireless access devices include intelligent processing that enables them to select a desired wireless switch for adoption. When in need of adoption, a wireless access device sends at least one SWITCH DISCOVER message over the network, the wireless switches reply with SWITCH OFFER messages, and the wireless access device processes the SWITCH OFFER messages to select a desired wireless switch for adoption. The SWITCH OFFER messages contain switch selection information associated with the respective wireless switches, and the wireless access device analyzes the switch selection information during the selection process.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to wireless local area networks.More particularly, the present invention relates to a technique foradopting wireless access ports by wireless switches in a wireless localarea network.

BACKGROUND OF THE INVENTION

Wireless local area networks (“WLANs”) can give clients the ability to“roam” or physically move from place to place without being connected bywires. In the context of a WLAN, the term “roaming” describes the act ofphysically moving between wireless access devices, which may bestand-alone wireless access points or wireless access ports thatcooperate with one or more wireless switches located in the WLAN. Manydeployments of wireless computer infrastructure, such as WLANs, involvethe use of multiple wireless switches serving a number of wirelessaccess devices. Conventional networks having multiple wireless switchesand multiple wireless access devices do not automatically orintelligently distribute the access devices among the switches. Rather,upon initialization or reset of a wireless access device, one commonadoption technique simply searches for the first available wirelessswitch that can adopt the access device. Although simple in design, thistechnique can lead to an uneven distribution of access devices among theswitches.

Prior art WLANs may utilize access control lists that restrict certainwireless access devices from being adopted by a particular wirelessswitch. Configuring these access control lists is a manual, timeconsuming process, and the access control lists do not result in adynamic or intelligent adoption scheme that provides automatic loadbalancing and redundancy. Indeed, such access control lists may actuallyprevent “backup” wireless switches from adopting wireless access devicesthat are adopted by a failed wireless switch. Thus, if one of theswitches fails, the access devices supported by that switch may idle ina disconnected state, resulting in poor wireless coverage for clientdevices.

Accordingly, it is desirable to have an automatic and intelligenttechnique for the adoption of wireless access devices by wirelessswitches in a computer network. In addition, it is desirable to have anautomatic adoption technique that results in load balancing amongwireless switches in the computer network. It is also desirable to havean automatic adoption technique that provides redundancy in the event offailure of one of the wireless switches in the computer network.Furthermore, other desirable features and characteristics of the presentinvention will become apparent from the subsequent detailed descriptionand the appended claims, taken in conjunction with the accompanyingdrawings and the foregoing technical field and background.

BRIEF SUMMARY OF THE INVENTION

A system and method is provided for adopting wireless access devices bywireless switches on a computer network. The adoption techniqueautomatically distributes wireless access devices among the wirelessswitches in a manner that results in load balancing and an efficient useof wireless switching resources. In this regard, a wireless accessdevice can select a desired wireless switch from multiple availableswitches based upon specified selection criteria.

The above and other aspects of the invention may be carried out in oneform by an adoption method for a wireless access device in a computernetwork. The method involves broadcasting a switch discover message overthe computer network, receiving, in response to the switch discovermessage, switch offer messages associated with wireless switches on thecomputer network, processing the switch offer messages, and selecting adesired wireless switch for adoption.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be derived byreferring to the detailed description and claims when considered inconjunction with the following figures, wherein like reference numbersrefer to similar elements throughout the figures.

FIG. 1 is a schematic representation of a computer network configured inaccordance with an example embodiment of the invention;

FIG. 2 is a schematic representation of a wireless access deviceconfigured in accordance with an example embodiment of the invention;

FIG. 3 is a schematic representation of a wireless switch configured inaccordance with an example embodiment of the invention;

FIG. 4 is a message diagram depicting an example communication sessionthat may be carried out by components in the computer network shown inFIG. 1; and

FIGS. 5 and 6 represent a flow diagram of an example wireless accessdevice adoption process that may be carried out by components in thecomputer network shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is merely illustrative in nature andis not intended to limit the invention or the application and uses ofthe invention. Furthermore, there is no intention to be bound by anyexpressed or implied theory presented in the preceding technical field,background, brief summary or the following detailed description.

The invention may be described herein in terms of functional and/orlogical block components and various processing steps. It should beappreciated that such block components may be realized by any number ofhardware, software, and/or firmware components configured to perform thespecified functions. For example, an embodiment of the invention mayemploy various integrated circuit components, e.g., memory elements,digital signal processing elements, logic elements, look-up tables, orthe like, which may carry out a variety of functions under the controlof one or more microprocessors or other control devices. In addition,those skilled in the art will appreciate that the present invention maybe practiced in conjunction with any number of data transmissionprotocols and that the system described herein is merely one exemplaryapplication for the invention.

For the sake of brevity, conventional techniques related to WLANs, datatransmission, signaling, network control, wireless access deviceoperation, wireless switch operation, and other functional aspects ofthe systems (and the individual operating components of the systems) maynot be described in detail herein. Furthermore, the connecting linesshown in the various figures contained herein are intended to representexample functional relationships and/or physical couplings between thevarious elements. It should be noted that many alternative or additionalfunctional relationships or physical connections may be present in apractical embodiment.

The following description may refer to elements or features being“connected” or “coupled” together. As used herein, unless expresslystated otherwise, “connected” means that one element/feature is directlyor indirectly connected to another element/feature, and not necessarilymechanically. Likewise, unless expressly stated otherwise, “coupled”means that one element/feature is directly or indirectly coupled toanother element/feature, and not necessarily mechanically. Thus,although the block diagrams depicted in the figures depict examplearrangements of elements, additional intervening elements, devices,features, or components may be present in an actual embodiment (assumingthat the functionality of the devices is not adversely affected).

FIG. 1 is a schematic representation of a computer network 100configured in accordance with an example embodiment of the invention. Inthis example, computer network 100 is configured as a WLAN. Computernetwork 100 generally includes wireless clients (identified by referencenumbers 102, 104, 106, 108, 110, and 112), a number of wireless switches(identified by reference numbers 114, 116, and 118), an Ethernet switch120, and a number of wireless access devices (identified by referencenumbers 122, 124, and 126). Computer network 100 may also include orcommunicate with any number of additional network components, such as atraditional local area network (“LAN”). In FIG. 1, such additionalnetwork components are generally identified by reference number 128. Apractical embodiment can have any number of wireless switches, eachsupporting any number of wireless access devices, and each wirelessaccess device supporting any number of wireless clients. Indeed, thetopology and configuration of computer network 100 can vary to suit theneeds of the particular application and FIG. 1 is not intended to limitthe application or scope of the invention in any way.

Wireless switches 114/116/118 are coupled to Ethernet switch 120, whichis in turn coupled to wireless access devices 122/124/126. In practice,wireless switches 114/116/118 communicate with wireless access devices122/124/126 via Ethernet switch 120. A given wireless switch can supportany number of wireless access devices, i.e., one or more wireless accessdevices can be concurrently adopted by a single wireless switch (in theexample embodiment, a wireless access device can be adopted by only onewireless switch at a time). The wireless clients are wireless devicesthat can physically move around computer network 100 and communicatewith network components 128 via wireless access devices 122/124/126.

In one practical embodiment, wireless access devices 122/124/126 arerealized as wireless access ports, which are “thin” devices that rely onthe network intelligence and management functions provided by wirelessswitches 114/116/118. Wireless access ports having conventional featuresthat can be incorporated into wireless access devices 122/124/126 areavailable from Symbol Technologies, Inc. Briefly, a wireless accessdevice as described herein is suitably configured to receive data fromwireless clients over wireless links. Once that data is captured by thewireless access device, the data can be processed for communicationwithin computer network 100. For example, the data can be encapsulatedinto a packet format compliant with a suitable data communicationprotocol. In the example embodiment, data is routed within computernetwork 100 using conventional Ethernet 802.3 addressing (includingstandard Ethernet destination and source packet addresses). In alternateembodiments, data can be routed within computer network 100 usingconventional Internet Protocol (“IP”) techniques.

The technique described herein governs the way by which wireless accessdevices are adopted by wireless switches in a manner that results inautomatic load balancing of the switches and redundancy. Briefly, when awireless access device is powered up or reset, it broadcasts a SWITCHDISCOVER message (or sends a number of SWITCH DISCOVER messages) overthe network. A SWITCH DISCOVER message informs a wireless switch that awireless access device is ready and available. A wireless switch thatreceives the SWITCH DISCOVER message will respond with a SWITCH OFFERmessage. The SWITCH OFFER message indicates willingness on the part ofthe responding wireless switch to adopt the wireless access device thatoriginated the SWITCH DISCOVER message. The SWITCH OFFER message mayinclude information such as the number of wireless access devicesalready adopted by the wireless switch, the average utilization/load onthe wireless switch, and/or whether the wireless switch is the preferredswitch for the wireless access device that originated the SWITCHDISCOVER message. In practice, the wireless access device collectsmultiple SWITCH OFFER messages from multiple wireless switches(resending the SWITCH DISCOVER message if needed) and selects one of thewireless switches as a desired switch for adoption. To promote uniformdistribution of wireless access devices among the wireless switches,each of the wireless access devices can send its respective SWITCHDISCOVER message after a random delay.

The wireless access device adoption scheme described herein allows thenumber of wireless access devices in the network to be evenlydistributed across the wireless switches. In addition, the wirelessaccess devices may employ selection criteria that favors lightly loadedswitches over highly loaded switches. Furthermore, a wireless accessdevice can be marked for adoption to a particular wireless switch, thusfacilitating a deterministic distribution that can be configured by anetwork operator.

FIG. 2 is a schematic representation of a wireless access device 200configured in accordance with an example embodiment of the invention. Apractical embodiment of wireless access device 200 will includeadditional components and elements configured to support known orconventional operating features that need not be described in detailherein. In the example embodiment, wireless access device 200 is awireless access port that transmits and receives data. An access portconnects users to other users within the network and also can serve asthe point of interconnection between a WLAN and a fixed wire network.Each access port can serve multiple users within a defined network area.As a wireless client moves beyond the range of one access port, thewireless client can be automatically handed over to another access port.In practice, the number of access ports in a given network generallyincreases with the number of network users and the physical size of thenetwork.

Wireless access device 200 generally includes a radio module 202, anetwork communication module 204, a processor architecture 206, andmemory 208. These and other elements of wireless access device 200 maybe interconnected together using a bus 210 or any suitableinterconnection arrangement. Such interconnection facilitatescommunication between the various elements of wireless access device200. Radio module 202, which includes a receiver and a transmitter (or atransceiver), is configured to communicate with wireless clients via awireless data communication link. In the example embodiment, radiomodule 202 is configured to support WLAN connectivity in compliance withestablished IEEE Standards, such as 802.11a, 802.11b, and 802.11a/b. Ofcourse, radio module 202 may be configured to support alternate oradditional wireless data communication protocols, including futurevariations of 802.11 such as 802.11a/b/g.

Network communication module 204 generally represents the hardware,software, firmware, processing logic, and/or other components ofwireless access device 200 that enable bi-directional communicationbetween wireless access device 200 and network components to whichwireless access device 200 is connected. Referring to FIG. 1 as anexample, network communication module 204 is suitably configured totransmit messages to components on computer network 100 (such aswireless switches 114/116/118, Ethernet switch 120, and/or additionalnetwork components 128), and to receive messages from components oncomputer network 100. In a typical deployment, network communicationmodule 204 provides an Ethernet interface such that wireless accessdevice 200 can communicate with a conventional Ethernet-based computernetwork. In this regard, network communication module 204 may include aphysical interface for connection to the computer network, and networkcommunication module 204 (and/or processor 206) may handle Ethernetaddressing for data packets sent from wireless access device 200.Network communication module 204 may also be configured to support IPnetwork communications.

Processor architecture 206 may be implemented or realized with a generalpurpose processor, a content addressable memory, a digital signalprocessor, an application specific integrated circuit, a fieldprogrammable gate array, any suitable programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof, designed to perform the functions described herein.In this regard, a processor may be realized as a microprocessor, acontroller, a microcontroller, a state machine, or the like. A processormay also be implemented as a combination of computing devices, e.g., acombination of a digital signal processor and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a digital signal processor core, or any other such configuration.

As depicted in FIG. 2, processor architecture 206 is in communicationwith network communication module 204. In this example, processorarchitecture 206 is also in communication with radio module 202 andmemory 208. Processor architecture 206 preferably includes processinglogic that is configured to carry out the techniques and processingtasks described in more detail below.

Memory 208 may be implemented or realized with RAM memory, flash memory,ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. In this regard, memory 208 can be coupled to processorarchitecture 206 such that processor architecture 206 can readinformation from, and write information to, memory 208. In thealternative, memory 208 may be integral to processor architecture 206.As an example, processor architecture 206 and memory 208 may reside in asuitably configured ASIC.

Memory 208 includes sufficient data storage capacity to support theoperation of wireless access device 200. In the example embodimentdescribed herein, memory 208 is configured to store selection criteria212 that influences the selection of an adopting wireless switch.Selection criteria 212 and its use are described in more detail below.Memory 208 may also be configured to store a device identifier 214 thatuniquely identifies wireless access device 200 within the networkenvironment. In practical embodiments, device identifier 214 mayrepresent the source address, serial number, network location, or anyresolvable identification for wireless access device 200. Deviceidentifier 214 and its use are described in more detail below.

FIG. 3 is a schematic representation of a wireless switch 300 configuredin accordance with an example embodiment of the invention. A practicalembodiment of wireless switch 300 will include additional components andelements configured to support known or conventional operating featuresthat need not be described in detail herein. In the example embodiment,wireless switch 300 contains intelligence and processing logic thatfacilitates centralized control and management of WLAN elements,including wireless access devices adopted by wireless switch 300. Inthis regard, one wireless switch 300 can support any number of wirelessaccess devices (limited only by practical considerations); a supportedwireless access device is “adopted” by the respective wireless switch300. Thus, each wireless switch 300 can serve multiple wireless accessdevices, which in turn can serve multiple wireless clients. Wirelessswitch 300 is suitably configured to transmit and receive data, and itmay serve as a point of interconnection between a WLAN and a fixed wirenetwork. In practice, the number of wireless switches 300 in a givennetwork generally increases with the number of network users and thephysical size of the network.

Wireless switch 300 generally includes a network communication module302, a data traffic monitor 304, a processor architecture 306, andmemory 308. These and other elements of wireless switch 300 may beinterconnected together using a bus 310 or any suitable interconnectionarrangement. Such interconnection facilitates communication between thevarious elements of wireless switch 300. Network communication module302 generally represents the hardware, software, firmware, processinglogic, and/or other components of wireless switch 300 that enablebi-directional communication between wireless switch 300 and networkcomponents to which wireless switch 300 is connected. Referring to FIG.1 as an example, network communication module 302 is suitably configuredto transmit messages to components on computer network 100 (such aswireless access devices 112/124/126, Ethernet switch 120, and/oradditional network components 128), and to receive messages fromcomponents on computer network 100. In a typical deployment, networkcommunication module 302 provides an Ethernet interface such thatwireless switch 300 can communicate with a conventional Ethernet-basedcomputer network. In this regard, network communication module 302 mayinclude a physical interface for connection to the computer network, andnetwork communication module 302 (and/or processor 306) may handleEthernet addressing for data packets sent from wireless switch 300.Network communication module 302 may also be configured to support IPnetwork communications.

Data traffic monitor 304 is configured to monitor the flow or amount ofdata processed by wireless switch 300. Data traffic monitor 304 may beimplemented or performed with a processor architecture 306, a contentaddressable memory, a digital signal processor, an application specificintegrated circuit, a field programmable gate array, any suitableprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof, designed to perform thefunctions described below.

Data traffic monitor 304 can monitor the data rate, the data volume, anaverage data rate, an average data volume, or any quantity orcharacteristic based upon empirical or statistical information. Themonitored data throughput may be unidirectional or bidirectional,depending upon the specific application. In practice, data trafficmonitor 304 may continuously update and store an average data rate or atotal data volume for a predetermined period of history, e.g., the last30 minutes. As described in more detail below, the information obtainedby data traffic monitor 304 can be utilized by a wireless access deviceto select a desired wireless switch for adoption.

Processor architecture 306 can be realized in the manner described abovein connection with processor architecture 206. As depicted in FIG. 3,processor architecture 306 is in communication with networkcommunication module 302, data traffic monitor 304, and memory 308.Processor architecture 306 preferably includes processing logic that isconfigured to carry out the techniques and processing tasks described inmore detail below.

Memory 308 may be implemented or realized in the manner described abovein connection with memory 208. Memory 308 includes sufficient datastorage capacity to support the operation of wireless switch 300. In theexample embodiment described herein, memory 308 is configured to storeat least a preferred device list or table 312, switch selectioninformation 314, and an adopted device list or table 316. Preferreddevice list 312 may represent a list of wireless access devices that aredesignated as “preferred” for the particular wireless switch 300. Thus,wireless switch 300 can be configured such that the adoption of certaindesignated wireless access devices will take priority over the adoptionof other wireless access devices. In other words, preferred device list312 enables a network operator to override the otherwise automaticadoption scheme described herein.

Switch selection information 314 generally represents information, data,characteristics, and/or performance statistics associated with wirelessswitch 300 that can be utilized by wireless access devices to select adesired wireless switch for adoption. In this manner, a wireless accessdevice can intelligently select a wireless switch for adoption basedupon one or more factors, including current operating conditions ofwireless switch 300 and current operating conditions of the computernetwork itself. In the practical embodiment, switch selectioninformation 314 may include, without limitation: a preference designator(which indicates whether wireless switch 300 is preferred for aparticular wireless access device); a load designator (which indicates aloading condition for wireless switch 300); and/or a data trafficdesignator (which indicates a data throughput condition for wirelessswitch 300). The processing of switch selection information 314 by awireless access device is described in more detail below.

Adopted device list 316 may represent a list of wireless access devicesthat are currently adopted by wireless switch 300. In practice, adopteddevice list 316 can include the device identifiers for the respectivewireless access devices. As mentioned above, these device identifiersuniquely identify the adopted wireless access devices, and the deviceidentifiers may represent, for example, the source address, serialnumber, network location, or any resolvable identification for thewireless access devices. Adopted device list 316 may also maintain acount corresponding to the number of wireless access devices currentlyadopted by wireless switch 300. This count may be utilized in connectionwith the load designator (described above in connection with switchselection information 314) to identify the current loading condition ofwireless switch 300.

FIG. 4 is a message diagram 400 depicting an example communicationsession that may be carried out by components in the computer networkshown in FIG. 1, and FIGS. 5 and 6 represent a flow diagram of anexample wireless access device adoption process 500 that may be carriedout in conjunction with the communication session depicted in FIG. 4.Message diagram 400 is arranged in chronological order, with timeprogressing from the top to the bottom. In this simplified example, onewireless access device 402 is depicted, along with three wirelessswitches 404/406/408. This simplified arrangement facilitates thefollowing description of the example communication session, and is notintended to limit the scope or application of the invention in any way.

The various tasks performed in connection with process 500 may beperformed by software, hardware, firmware, or any combination thereof.For illustrative purposes, the following description of process 500 mayrefer to elements mentioned above in connection with FIGS. 1-3. Inpractical embodiments, portions of process 500 may be performed bydifferent elements of the described network, e.g., a wireless switch, awireless access device, or the like. It should be appreciated thatprocess 500 may include any number of additional or alternative tasks,the tasks shown in FIGS. 5 and 6 need not be performed in theillustrated order, and process 500 may be incorporated into a morecomprehensive procedure or process having additional functionality notdescribed in detail herein.

Wireless access device adoption process 500 assumes that the computernetwork includes at least two wireless switches. In the preferredembodiment, process 500 is initiated whenever a wireless access deviceon the network is powered up, connected, initialized, reset, or thelike. For example, process 500 may be initiated in connection with theintroduction of a new wireless access device into the network, after anexisting wireless access device loses connectivity with a wirelessswitch, after an existing wireless access device is shut down andpowered up again, or upon power up of the network itself.

Process 500 may begin with the generation of one or more SWITCH DISCOVERmessages, followed by the broadcasting or sending of the SWITCH DISCOVERmessage(s) over the computer network by wireless access device 402 (task502). In one practical embodiment, task 502 is associated with thebroadcasting of a single SWITCH DISCOVER message over the computernetwork. Some network communication protocols, however, do not allowmessages to be broadcast across networks. For example, such broadcastingis not supported by IP. In such networks, therefore, task 502 may beassociated with the generation and sending of a number of SWITCHDISCOVER messages that are individually directed to potential wirelessswitches that can adopt the wireless access device. In this regard, thewireless access device would employ a suitable technique to obtain ordiscover a list of potential wireless switches in an IP network. Forexample, the wireless access device may obtain the list from a DHCPserver, which can provide the information using DHCP-Options fields. Asanother example, the wireless access device may be designed to perform aDNS lookup of a well-known name or a configured name, such as“Symbol-Wireless-Switch.” In response, the DNS server can provide a listof the IP addresses of all candidate wireless switches in the network.

The example described herein assumes that the SWITCH DISCOVER message isbroadcast over the network. An equivalent methodology, however, can beimplemented for IP networks that do not support broadcast messages.Although FIG. 4 only depicts the broadcasting of the SWITCH DISCOVERmessage to wireless switches 404/406/408, the SWITCH DISCOVER message isactually broadcast over the computer network for potential reception byany number of network components. One practical embodiment employsconventional Layer 2 Ethernet broadcast techniques to accomplish task502.

In accordance with the example embodiment described herein, the SWITCHDISCOVER message includes an identifier for wireless access device 402.This identifier may be, for example, a source address, a serial number,a network location, or any resolvable identification for wireless accessdevice 402. The SWITCH DISCOVER message also includes data orinformation indicative of its functionality. In other words, the SWITCHDISCOVER message includes data or information that can be recognized andprocessed by compatible wireless switches on the computer network in themanner described herein. In this regard, the SWITCH DISCOVER message mayinform the compatible wireless switches that wireless access device 402is seeking a wireless switch for adoption. In practice, the SWITCHDISCOVER message may be configured such that it is disregarded, ignored,or not received by certain network components (for example, networkcomponents other than wireless switches).

Eventually, one or more wireless switches receive the SWITCH DISCOVERmessage over the computer network (task 504). For ease of illustration,the flow chart of FIGS. 5 and 6 is separated into two sections connectedby dashed arrows; the blocks on the left side of FIGS. 5 and 6 representtasks that are typically performed by a wireless access device, and theblocks on the right side of FIGS. 5 and 6 represent tasks that aretypically performed by each compatible wireless switch. FIG. 4 depictsthe broadcasting of a SWITCH DISCOVER message 410 and the receipt ofthat message by wireless switches 404/406/408.

After receiving the SWITCH DISCOVER message, a compatible wirelessswitch will process the SWITCH DISCOVER message in an appropriate manner(task 506). Such processing may, for example, interpret the SWITCHDISCOVER message to obtain its meaning in the context of the computernetwork. In other words, the wireless switch has the intelligence todetermine that this particular message is a SWITCH DISCOVER messagerather than some other message or piece of information. Such processingmay also include, for example, an extraction of the identifier forwireless access device 402 from the SWITCH DISCOVER message and/or someother procedure that identifies wireless access device 402.

In the example embodiment, the wireless switch determines whether theSWITCH DISCOVER message originated from a preferred wireless accessdevice (query task 508). In practice, the wireless switch may analyzethe identifier contained in the SWITCH DISCOVER message and compare theidentifier to a list of preferred devices (see above description ofwireless switch 300). If the originating wireless access device 402 is apreferred device for the wireless switch, then the wireless switch mayset a preference designator to indicate that wireless access device 402is preferred (task 510). In a practical embodiment, the wireless switchmay set a bit, a byte, a field, or any suitable data group to indicate a“preferred” state. If the originating wireless access device 402 is nota preferred device for the wireless switch, then the wireless switch mayset a preference designator to indicate that wireless access device 402is not preferred (task 512). In a practical embodiment, the wirelessswitch may set a bit, a byte, a field, or any suitable data group toindicate a “not preferred” state.

In addition to the preference designator, the wireless switch may obtaina loading condition for use with a load designator for the wirelessswitch (task 514). As mentioned above, the loading condition mayrepresent the current number of devices supported by the wirelessswitch. Thus, in a practical embodiment, the load designator may beindicative of a numerical count, a percentage of maximum load capacity,or any suitable measurement of the current loading condition. The loaddesignator can be realized as a number of bits, a byte, a field, or anysuitable data group.

The wireless switch may also obtain a data throughput condition for usewith a data traffic designator for the wireless switch (task 516). Asmentioned above in connection with data traffic monitor 304 (see FIG.3), the data throughput condition may represent the data rate, the datavolume, an average data rate, an average data volume, or any quantity orcharacteristic based upon empirical or statistical information for thewireless switch. Thus, in a practical embodiment, the data trafficdesignator may be indicative of the amount of data processed by thewireless switch during a recent time period, or any suitable measurementof the data flow through the wireless switch. The data trafficdesignator can be realized as a number of bits, a byte, a field, or anysuitable data group.

The preference designator, the load designator, the data trafficdesignator, and possibly other data or information associated with (ormaintained by) the wireless switch are individually and collectivelyreferred to herein as “switch selection information.” In this regard,the switch selection information may include variable information thatchanges in response to the changing operating conditions of the wirelessswitch and the computer network. The wireless switch generates asuitably configured SWITCH OFFER message (task 518) that indicates thewillingness of the wireless switch to adopt the originating wirelessaccess device 402. In the example embodiment, the SWITCH OFFER messageincludes the switch selection information and an identifier for thewireless switch. This identifier may be, for example, a source address,a serial number, a network location, or any resolvable identificationfor the wireless switch.

The wireless switch may then address the SWITCH OFFER message to theoriginating wireless access device 402 (task 520) such that the SWITCHOFFER message can be properly routed back to wireless access device 402over the computer network. Tasks 504-520 can be performed by any numberof compatible wireless switches in the computer network in response tothe broadcasting of a single SWITCH DISCOVER message, however, FIG. 5only depicts one iteration of this processing for the sake of clarityand simplicity.

In response to the SWITCH DISCOVER message, wireless access device 402receives a number (M) of SWITCH OFFER messages associated with a number(N) of wireless switches on the computer network (task 522). In thiscontext, M can be any number, including zero, that is less than or equalto N. For example, if all of the wireless switches on the network arecompatible with wireless access device adoption process 500, and all ofthe wireless switches perform tasks 504-520, then wireless access device402 can receive N SWITCH OFFER messages in response to a single SWITCHDISCOVER message broadcast over the network. FIG. 4, however, depicts asituation where wireless switch 404 generates a SWITCH OFFER message412, wireless switch 408 generates a SWITCH OFFER message 414, andwireless switch 406 does not respond to the SWITCH DISCOVER message.This situation might indicate that wireless switch 406 is incompatiblewith process 500, that wireless switch 406 is explicitly configured tonot adopt the particular originating wireless access device 402, thatwireless switch 406 did not properly receive the SWITCH DISCOVERmessage, that wireless access device 402 did not properly receive aSWITCH OFFER message from wireless switch 406, or the like. A practicalwireless access device may utilize a short delay period afterbroadcasting the SWITCH DISCOVER message to ensure that it has time toreceive all of the SWITCH OFFER messages, which may be generated bymultiple wireless switches.

Eventually, the originating wireless access device 402 begins to processthe collected SWITCH OFFER messages; wireless access device 402 canarbitrarily select the next SWITCH OFFER message for processing (task524). In connection with such processing, wireless access device 402 maysave the source address or other identifier for the current SWITCH OFFERmessage (task 526). Wireless access device 402 may also process andanalyze the switch selection information contained in the current SWITCHOFFER message as described in more detail below.

In the example embodiment, wireless access device 402 determines whetherthe current SWITCH OFFER message originated from a preferred wirelessswitch (query task 528). In this regard, wireless access device 402 mayconsult the preference designator contained in the current SWITCH OFFERmessage. If wireless access device 402 determines that the currentSWITCH OFFER message originated from a preferred switch, then wirelessaccess device 402 will select that preferred switch as the desiredswitch for adoption (task 530). In this manner, wireless access device402 can employ selection criteria that favors preferred wirelessswitches over non-preferred wireless switches. This enables a networkoperator to designate default relationships between wireless switchesand wireless access devices as necessary. If a preferred wireless switchis selected, then task 530 leads to a task 542 (described below).

If query task 528 determines that the current SWITCH OFFER messageoriginated from a non-preferred wireless switch, then wireless accessdevice 402 may save the load designator (task 532) and the data trafficdesignator (task 534) included in the current SWITCH OFFER message.These designators are preferably maintained for comparison to likedesignators contained in other SWITCH OFFER messages. If more SWITCHOFFER messages remain unprocessed (query task 536), then wireless accessdevice adoption process 500 can be re-entered at task 524 such that thenext SWITCH OFFER message is processed as described above. If all of theSWITCH OFFER messages have been processed, then wireless access device402 can compare the switch selection information (e.g., the loaddesignators and/or the data traffic designators from the various SWITCHOFFER messages) to selection criteria maintained by wireless accessdevice 402 (task 538).

In the practical embodiment, the selection criteria influences theselection of a desired wireless switch from among the wireless switchesthat originated the SWITCH OFFER messages. For example, the selectioncriteria may favor lightly loaded wireless switches over heavily loadedwireless switches. As another example, the selection criteria mightfavor light data traffic wireless switches over heavy data trafficwireless switches. The selection criteria may also be prioritized togive more weight to certain operating characteristics of the computernetwork. In one example embodiment, a preferred wireless switch willhave priority over all other wireless switches regardless of the loadconditions and regardless of the data traffic conditions. If noresponding wireless switch is a preferred switch, however, then wirelessaccess device 402 will select the wireless switch having the lightestcurrent loading. If, however, the lightest load condition is shared bytwo wireless switches, then wireless access device 402 will select (fromthose two wireless switches) the wireless switch having the least amountof data traffic activity.

After consulting the selection criteria and analyzing the switchselection information, wireless access device 402 can select a desiredswitch for adoption (task. 540). Once a desired switch has beenselected, wireless access device 402 can generate an ADOPTION messagefor the desired switch (task 542) and address the ADOPTION message tothe selected switch (task 544). In practice, wireless access device 402may leverage known techniques and protocols to generate, format, andaddress the ADOPTION message.

In response to the generation of its SWITCH OFFER message, the selectedwireless switch receives the ADOPTION message, processes the message,and adopts wireless access device 402 (task 546). FIG. 4 depicts anexample where an ADOPTION message 416 is addressed to, and received by,wireless switch 404. The selected wireless switch will process theADOPTION message in an appropriate manner (possibly utilizingconventional techniques) to support wireless access device 402 and toestablish communication between wireless access device 402 and theselected wireless switch. FIG. 4 depicts this communication withreference number 418. In response to such adoption, the selectedwireless switch may update its switch selection information and/orupdate its adopted device list to reflect the additional load (task548).

If communication between the selected wireless switch and wirelessaccess device 402 is interrupted, then wireless access device adoptionprocess 500 can be repeated to ensure that wireless access device 402 isre-adopted. In a practical embodiment, a wireless access device may beconfigured to periodically rebroadcast a SWITCH DISCOVER message duringnormal operation. Such periodic rebroadcasts may be desirable todynamically optimize the allocation of wireless access devices towireless switches throughout the computer network.

While at least one example embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexample embodiment or embodiments described herein are not intended tolimit the scope, applicability, or configuration of the invention in anyway. Rather, the foregoing detailed description will provide thoseskilled in the art with a convenient road map for implementing thedescribed embodiment or embodiments. It should be understood thatvarious changes can be made in the function and arrangement of elementswithout departing from the scope of the invention as set forth in theappended claims and the legal equivalents thereof.

1. In a computer network, an adoption method for a wireless accessdevice, said method comprising: broadcasting a switch discover messageover the computer network; receiving, in response to said switchdiscover message, M switch offer messages associated with N wirelessswitches on the computer network, each of said switch offer messagescomprising a preference designator that indicates whether or not therespective wireless switch is preferred for the wireless access device,and each of said switch offer messages comprising switch selectioninformation that is utilized by the wireless access device to select oneof said wireless switches for adoption; processing said preferencedesignators and said switch selection information in said switch offermessages; if the preference designator of one of said switch offermessages indicates a preferred wireless switch, selecting said preferredwireless switch for adoption regardless of said switch selectioninformation; and if the preference designators of said switch offermessages indicate no preferred wireless switch, selecting a desiredwireless switch for adoption based upon said switch selectioninformation.
 2. A method according to claim 1, wherein M is less than orequal to N.
 3. A method according to claim 1, wherein processing saidpreference designators and said switch selection information comprisesanalyzing said switch selection information.
 4. A method according toclaim 3, further comprising comparing said switch selection informationto selection criteria, wherein selecting said desired wireless switch isinfluenced by said selection criteria.
 5. A method according to claim 4,said selection criteria favoring preferred wireless switches overnon-preferred wireless switches.
 6. A method according to claim 4, saidselection criteria favoring lightly loaded wireless switches overheavily loaded wireless switches.
 7. A method according to claim 4, saidselection criteria favoring light data traffic wireless switches overheavy data traffic wireless switches.
 8. A method according to claim 1,further comprising generating an adoption message for said desiredwireless switch or for said preferred wireless switch.
 9. A wirelessaccess device for a computer network, said wireless access devicecomprising: a network communication module configured to transmitmessages to components on the computer network, and to receive messagesfrom components on the computer network; and processing logic incommunication with said network communication module, said processinglogic being configured to: generate one or more switch discover messagesfor sending over the computer network; receive, in response to said oneor more switch discover messages, M switch offer messages associatedwith N wireless switches on the computer network, each of said switchoffer messages comprising a preference designator that indicates whetheror not the respective wireless switch is preferred for the wirelessaccess device, and each of said switch offer messages comprising switchselection information that is utilized by the wireless access device toselect one of said wireless switches for adoption; process said switchoffer messages; if the preference designator of one of said switch offermessages indicates a preferred wireless switch, select said preferredwireless switch for adoption regardless of said switch selectioninformation; and if the preference designators of said switch offermessages indicate no preferred wireless switch, select, from saidwireless switches, a desired wireless switch for adoption.
 10. Awireless access device according to claim 9, wherein said processinglogic is configured to analyze said switch selection information.
 11. Awireless access device according to claim 10, said processing logicbeing configured to compare said switch selection information toselection criteria, wherein selecting said desired wireless switch isinfluenced by said selection criteria.
 12. A wireless access deviceaccording to claim 9, said processing logic being configured to generatean adoption message for said desired wireless switch or for saidpreferred wireless switch.